Originally posted by AndrewT Hi,
noise and ripple is approaching -130db.
That is good, maybe very good, some might even say excellent.
An alternative would be Jung. There is a thread here with all the construction details and it has similar performance. I would guess both have quite fast response.
regards Andrew T.

I seriously doubt it has 130db of PSRR. It doesn't have a current mirror and current source for the differential for starters. The RC filter after the voltage source feeding the jfet diff is a nice touch though.

I think it is extremely difficult to get 100db + PSRR in a discrete design and get low output impedance. Then HF performance is likely to be alot worse.

Here are some photos I shot of the regulated power supply and the recifying supply kits.

Sigge

Quote:

Originally posted by Sigurd Ruschkow Hi all,

I am looking for a good regulated power supply (+-24 V) for a buffer. Borbely's designs seems to have a good reputation. One of his power supplies is shown below.
Is can support 200 mA so it is a bit oversized but that is to my liking :-)

Elso -
at last, I now have the 254 together with a Borblly Superbuffer1 and an unregulted PS 309 also from Borbely.
Here are some sonical impressions I have. I compared the Superbuffer1/254/309 with a TX102 transformer volume attenuator.

I use the Superbuffer1 with Teflon PCB and Caddock high resolution MK132 resistors for the input, output, and feedback resistors. I also opted for the high output current option that is supposed to give better bass (and the SB1 can now also drive 600 Ohms, which I do not need). Instead of the voltage references, I have installed blue LEDs.

Transformers are 225 VA toroids from Amplimo that are potted, and shielded against both magnetic and electric fields.

The Borbely preamp is built up like dual mono from the AC outlet and onwards.
A mains net filter from Schaffner is also used for each channel.
For the stepped attenuator I use DALE's CMF55 non metallic resistors.

To summarize
==========
Both me and my wife find that Borbely's Superbuffer1 sounds better than the S&B TX102 transformers. More detail, more slam, another octave of deep firm bass, and better focus and clarity on voices.

Sound comparisons
==============
Both these preamps are of very high quality both regarding component choice, mechanical properties, and sonically. No doubt about that! Still, it was not that hard to hear that they did not sound the alike.

I built the TX102 preamp some months ago. The sonic character I hear is a smooth, bass-rich sound with great sound stage, a polished treble that is never hard or cold, and a body for each individual instrument (on good recordings) that can be very appealing. Details are OK. Transients could be better.

The preamp made up out of Borbelyäs designs has been online since a month and the SB1 is now fully burned-in. It sonic character is one full of details, resolution is higher than I ever had heard before, each instrument is clearly heard through a mass of instruments with a very good focus and body. The body I heard on the TX102 preamp is more muddy in comparison. Voices are better as they are easier to hear, more realesed, with better clarity. Soundstage is great with wonderful depth. Transients scaringly fast. Slam is fantastic. Bass is firm, powerful and deep. I did not know that my speaker could deiiver such a deep bass.

Sigurd

Quote:

Originally posted by Elso Kwak
Hi Sigurd,
But how does it sound?
Or do you believe low noise automatically implies good sound?